// Copyright 2015 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/compiler/node-matchers.h"

namespace v8 {
namespace internal {
    namespace compiler {

        bool NodeMatcher::IsComparison() const
        {
            return IrOpcode::IsComparisonOpcode(opcode());
        }

        BranchMatcher::BranchMatcher(Node* branch)
            : NodeMatcher(branch)
            , if_true_(nullptr)
            , if_false_(nullptr)
        {
            if (branch->opcode() != IrOpcode::kBranch)
                return;
            for (Node* use : branch->uses()) {
                if (use->opcode() == IrOpcode::kIfTrue) {
                    DCHECK_NULL(if_true_);
                    if_true_ = use;
                } else if (use->opcode() == IrOpcode::kIfFalse) {
                    DCHECK_NULL(if_false_);
                    if_false_ = use;
                }
            }
        }

        DiamondMatcher::DiamondMatcher(Node* merge)
            : NodeMatcher(merge)
            , branch_(nullptr)
            , if_true_(nullptr)
            , if_false_(nullptr)
        {
            if (merge->InputCount() != 2)
                return;
            if (merge->opcode() != IrOpcode::kMerge)
                return;
            Node* input0 = merge->InputAt(0);
            if (input0->InputCount() != 1)
                return;
            Node* input1 = merge->InputAt(1);
            if (input1->InputCount() != 1)
                return;
            Node* branch = input0->InputAt(0);
            if (branch != input1->InputAt(0))
                return;
            if (branch->opcode() != IrOpcode::kBranch)
                return;
            if (input0->opcode() == IrOpcode::kIfTrue && input1->opcode() == IrOpcode::kIfFalse) {
                branch_ = branch;
                if_true_ = input0;
                if_false_ = input1;
            } else if (input0->opcode() == IrOpcode::kIfFalse && input1->opcode() == IrOpcode::kIfTrue) {
                branch_ = branch;
                if_true_ = input1;
                if_false_ = input0;
            }
        }

    } // namespace compiler
} // namespace internal
} // namespace v8
